diff options
Diffstat (limited to 'fs/btrfs/qgroup.c')
-rw-r--r-- | fs/btrfs/qgroup.c | 108 |
1 files changed, 83 insertions, 25 deletions
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c index 82d4559eb4b1..40e5f7f2fcb7 100644 --- a/fs/btrfs/qgroup.c +++ b/fs/btrfs/qgroup.c @@ -1324,7 +1324,7 @@ static int flush_reservations(struct btrfs_fs_info *fs_info) trans = btrfs_join_transaction(fs_info->tree_root); if (IS_ERR(trans)) return PTR_ERR(trans); - btrfs_commit_transaction(trans); + ret = btrfs_commit_transaction(trans); return ret; } @@ -1342,16 +1342,10 @@ int btrfs_quota_disable(struct btrfs_fs_info *fs_info) lockdep_assert_held_write(&fs_info->subvol_sem); /* - * Lock the cleaner mutex to prevent races with concurrent relocation, - * because relocation may be building backrefs for blocks of the quota - * root while we are deleting the root. This is like dropping fs roots - * of deleted snapshots/subvolumes, we need the same protection. - * - * This also prevents races between concurrent tasks trying to disable - * quotas, because we will unlock and relock qgroup_ioctl_lock across - * BTRFS_FS_QUOTA_ENABLED changes. + * Relocation will mess with backrefs, so make sure we have the + * cleaner_mutex held to protect us from relocate. */ - mutex_lock(&fs_info->cleaner_mutex); + lockdep_assert_held(&fs_info->cleaner_mutex); mutex_lock(&fs_info->qgroup_ioctl_lock); if (!fs_info->quota_root) @@ -1373,9 +1367,13 @@ int btrfs_quota_disable(struct btrfs_fs_info *fs_info) clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags); btrfs_qgroup_wait_for_completion(fs_info, false); + /* + * We have nothing held here and no trans handle, just return the error + * if there is one. + */ ret = flush_reservations(fs_info); if (ret) - goto out_unlock_cleaner; + return ret; /* * 1 For the root item @@ -1439,9 +1437,6 @@ out: btrfs_end_transaction(trans); else if (trans) ret = btrfs_commit_transaction(trans); -out_unlock_cleaner: - mutex_unlock(&fs_info->cleaner_mutex); - return ret; } @@ -2505,8 +2500,8 @@ int btrfs_qgroup_trace_subtree(struct btrfs_trans_handle *trans, struct extent_buffer *eb = root_eb; struct btrfs_path *path = NULL; - BUG_ON(root_level < 0 || root_level >= BTRFS_MAX_LEVEL); - BUG_ON(root_eb == NULL); + ASSERT(0 <= root_level && root_level < BTRFS_MAX_LEVEL); + ASSERT(root_eb != NULL); if (!btrfs_qgroup_full_accounting(fs_info)) return 0; @@ -2861,8 +2856,6 @@ int btrfs_qgroup_account_extent(struct btrfs_trans_handle *trans, u64 bytenr, if (nr_old_roots == 0 && nr_new_roots == 0) goto out_free; - BUG_ON(!fs_info->quota_root); - trace_btrfs_qgroup_account_extent(fs_info, trans->transid, bytenr, num_bytes, nr_old_roots, nr_new_roots); @@ -3143,6 +3136,62 @@ static int qgroup_auto_inherit(struct btrfs_fs_info *fs_info, } /* + * Check if we can skip rescan when inheriting qgroups. If @src has a single + * @parent, and that @parent is owning all its bytes exclusively, we can skip + * the full rescan, by just adding nodesize to the @parent's excl/rfer. + * + * Return <0 for fatal errors (like srcid/parentid has no qgroup). + * Return 0 if a quick inherit is done. + * Return >0 if a quick inherit is not possible, and a full rescan is needed. + */ +static int qgroup_snapshot_quick_inherit(struct btrfs_fs_info *fs_info, + u64 srcid, u64 parentid) +{ + struct btrfs_qgroup *src; + struct btrfs_qgroup *parent; + struct btrfs_qgroup_list *list; + int nr_parents = 0; + + src = find_qgroup_rb(fs_info, srcid); + if (!src) + return -ENOENT; + parent = find_qgroup_rb(fs_info, parentid); + if (!parent) + return -ENOENT; + + /* + * Source has no parent qgroup, but our new qgroup would have one. + * Qgroup numbers would become inconsistent. + */ + if (list_empty(&src->groups)) + return 1; + + list_for_each_entry(list, &src->groups, next_group) { + /* The parent is not the same, quick update is not possible. */ + if (list->group->qgroupid != parentid) + return 1; + nr_parents++; + /* + * More than one parent qgroup, we can't be sure about accounting + * consistency. + */ + if (nr_parents > 1) + return 1; + } + + /* + * The parent is not exclusively owning all its bytes. We're not sure + * if the source has any bytes not fully owned by the parent. + */ + if (parent->excl != parent->rfer) + return 1; + + parent->excl += fs_info->nodesize; + parent->rfer += fs_info->nodesize; + return 0; +} + +/* * Copy the accounting information between qgroups. This is necessary * when a snapshot or a subvolume is created. Throwing an error will * cause a transaction abort so we take extra care here to only error @@ -3310,6 +3359,13 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid, qgroup_dirty(fs_info, dstgroup); qgroup_dirty(fs_info, srcgroup); + + /* + * If the source qgroup has parent but the new one doesn't, + * we need a full rescan. + */ + if (!inherit && !list_empty(&srcgroup->groups)) + need_rescan = true; } if (!inherit) @@ -3324,14 +3380,16 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid, if (ret) goto unlock; } + if (srcid) { + /* Check if we can do a quick inherit. */ + ret = qgroup_snapshot_quick_inherit(fs_info, srcid, *i_qgroups); + if (ret < 0) + goto unlock; + if (ret > 0) + need_rescan = true; + ret = 0; + } ++i_qgroups; - - /* - * If we're doing a snapshot, and adding the snapshot to a new - * qgroup, the numbers are guaranteed to be incorrect. - */ - if (srcid) - need_rescan = true; } for (i = 0; i < inherit->num_ref_copies; ++i, i_qgroups += 2) { |